A Review on Deep Drawing Process

Forming conical parts is one of the difficult fields in sheet metal forming processes. Because of low contact area of the sheet with the punch in the initial stages of forming, too much tension applied to the sheet that it causes bursting. Furthermore, since the major part of the sheet surface between the blank holder and punch tip is free, wrinkles appears on the wall of the drawn parts. These parts are normally formed in industry by processes such as spinning, explosive forming or multistage deep drawing. Hydroforming deep drawing is one of the special deep drawing processes which have been introduced in order to overcome some inherent problems in the conventional deep drawing with rigid tools. In the present work, an experimental program has been carried out to form and compare the forming pure copper conical-cylindrical cups by hydroforming and conventional multistage deep drawing processes. The conical parts in conventional deep drawing process formed in two stages. The results of the study demonstrate that thickness distribution are more uniform in the parts formed by hydroforming compared to conventional multi stages deep drawing processes.

Experimental and Finite Element Studies of Redrawing for ASS 316 at Elevated Temperatures

Cross-profile deep drawing of magnesium alloy AZ31 sheet metal for springback analysis under various temperatures

Measuring deformation mostly is based on the contact type of measurements which utilize the gauges and instruments. But this type of contact will lead to error in the precise measurement because of errors by the contact, measuring instruments, and human. So, feel proud to introduce image processing in the field of measurement. Here, in this study deals the measurement of deformation of deep drawing specimen by image processing which is called as contact free method. This is invasive method of measurement in two dimensions.Deep drawing process is an important sheet metal forming in which flat sheet metal had been forced through the die in association with the forward punch force and opposing blank holder force. As the blank passes through the tool set converts 2D bank into 3D cup formation. The process of achieving the required diameter of the cup can be produced in single stage or multistage operation. In this study, experimental study had been conducted on single stage deep drawing process for assessment of deformation and strain in aluminum alloy, copper alloy and brass alloy. Cylindrical cup deep drawing experimental tests were performed with blank of 60 x 60 square plate with 1 mm thickness. Eventually this new approach will help to optimize the geometry parameters deep drawing specimen correlation with the Matlab results.

Deep drawing process is an important process adding values to flat sheet metals in many industries. An important concern in the design of a deep drawing process generally is formability. This paper aims to present the connection between formability and inverse analysis (IA), which is a systematical means for determining an optimal blank configuration for a deep drawing process. In this paper, IA is presented and explored by using a commercial finite element software package. A number of numerical studies on the effect of blank configurations to the quality of a part produced by a deep drawing process were conducted and analyzed. The quality of the drawing processes is numerically analyzed by using an explicit incremental nonlinear finite element code. The minimum distance between elemental principal strains and the strain-based forming limit curve (FLC) is defined as tearing margin to be the key performance index (KPI) implying the quality of the part. The initial blank configuration has shown that it plays a highly important role in the quality of the product via the deep drawing process. In addition, it is observed that if a blank configuration is not greatly deviated from the one obtained from IA, the blank can still result a good product. The strain history around the bottom fillet of the part is also observed. The paper concludes that IA is an important part of the design methodology for deep drawing processes.

Series production of sheet metal components in press shops is permanently subjected to an increasing pressure in time, cost and quality. Varying sheet metal properties due to batch fluctuations and changing process conditions lead to an increase of try out time phase and scrap rate, resulting in a demand for adaptive control strategies for deep drawing. Today, these chal-lenges are met by integrating sensors and actuators into tool structure which measure and control part quality, mainly through blank draw-in. However, such tool-based control systems require a complex and cost-intensive modification of the existing die or press technology. Against this background, the active adjustment of blank position prior the deep drawing process realized with an intelligent transfer and positioning system as a promising approach towards economic and technical aspects. This paper deals with blank positioning and its sensitivity to quality-related failures of deep drawn sheet metal components like splits and wrinkles. Therefore, a numerical study was conducted on a deep drawing process of an exemplary structural part geometry, wherein a typical fluctuation of material parameters and variation of local friction conditions was simulated. Subsequently, correlations between process disturbance and blank draw-in were elaborated, thus using local draw-in values as controlled variables for a closed loop system. Sim-ulation results showed that the manipulating parameter, i.e. the blank position prior deep draw-ing, reveals a significant influence on the draw-in and therefore on the component s quality. An essential finding of this study is the numerical proof of concept for this new deep drawing control strategy, demonstrated for different process conditions. Finally, disturbances in the deep drawing process considered could be successfully controlled by adapting the blank position.

The deep drawing process is commonly used in the industry because its ability to produce parts with reduced weight and good mechanical properties at a high production rates. However, the elasto-plastic deformation mechanism of deep drawing is complex and difficult to analyse; this because there are many process parameters and variables involved that affect the quality of final products. Among these variables are the geometric parameters, which have been proved to have a great influence on the process. Theoretical and experimental analyses reported in the literature have been mainly focused on conventional cylindrical cup deep drawing. Few research works have dealt with the deep drawing analysis of non-cylindrical parts, particularly the influence of geometrical parameters on the deep drawing performance. This paper presents an analysis of the effect of geometrical parameters on the allowable deep drawing height (DDH) of rectangular parts before fracture. The aim is to identify the influence of the main geometrical parameters on the DDH, Numerical analyses based on the Finite Element Method (FEM) were used to investigate the influence of geometrical parameters, such as the radii, the metal sheet thickness, and the aspect ratio, among others, on the DDH.

This study was the use of the finite element method in the deep drawing process of a rectangular shell cup. The aim was to analyse the equivalent strain in the workpiece and to find out what happened to the disc blank sheet before the forming by stamping. The rectangular shell cup was 24x30x20 mm. and made of 2mm.thick SUS 403 and SUS 304 stainless steel. There were 3 types of blank sheets: 1) square sheet 2) 45 degree angled edge cutting sheet 3) circular sheet. It was found out that the drawing up with the use of 3 types of blank sheet made of SUS 304 stainless steel had no risk in the workpiece. For the stamping of the rectangular shell that used a square sheet made of SUS 403 stainless steel, it was found out that there was no risk in the work piece, but with the use of 45 degree angled edge cutting sheet or round sheet, the work piece had a risk to be damaged. Keywords: rectangular shell, Finite element 1. INTRODUCTION Deep drawing is very important to component manufacturing of parts of a product in industries. The problem of the rectangular shell cup deep drawing process was the equal amount of flow in each side, resulting in making mould in an actual production process. Therefore, finite element process plays a role in analyzing the ability of a rectangular shell deep drawing process and it well known that using steel sheet in deep drawing process requires an awareness of the factors that have an effect with finished workpieces to prevent the damage that may happen with workpieces during the deep drawing process There are the factors or variable that have an influence on ability in drawing. During the deep drawing, the punch will be stamped on the blank sheet through the die opening. This process will make the bending and unbending in the die. The metal between the punch will have tensile stress along the line of the punch and the hoop compression stress. The metal on the shell wall will receive axial tension. At the bottom of the shell the metal will have tensile stress on both axial lines. This stress has an effect to the force in drawing and damage that will be

Texture evolution of the deep drawing of molybdenum sheet was investigated with EBSD (Electron Back Scattered Diffraction), X-ray diffraction techniques and orientation distribution function (ODF) analysis. The texture during deep drawing is hardly changed due to the strong of initial texture. Specimens symmetry of 45° from rolling direction have monoclinic symmetry during deep drawing proce ss. EBSD can be used for the quantitative determination of macroscopic texture as like X-ray diffraction techniques if a sufficient number of grains are measured. Grain sizes show the similar values during deep drawing process but their values along 45° direction from rolling direction at flange and wall are tend to increase. It is associated with the 45° earing of deep drawing processing. The correlation function values were -0.58 for RD flange and -0.36 for RD wall and suggest that high Taylor factor regions have low pattern quality and low Taylor factor regions have high pattern quality.

A developed process for deep drawing of metal foil square cups

In this paper, the traditional empirical coefficient method and a novel loop material analytical method presented by the authors have been compared and discussed by analyzing several practical cylindrical workpieces’ deep drawing projects. Also, some conclusions about how to modify the traditional analyzing method of cylindrical workpieces’ deep drawing process could be concluded and the necessity of this modification could be proved.

Abstract. A promising approach to meet ecological and economical challenges in production industry is the combination of additive manufacturing and forming, which enables the production of hybrid parts. The fusion of the two technologies has the potential to use the benefits of both process classes. One example for the combination of additive manufacturing and forming is a process chain consisting of laser-based directed energy deposition (DED-LB/M) to apply a wear resistant coating on a sheet metal and a subsequent deep drawing process to achieve the final geometry of the component. However, the presence of the local reinforcement influences the subsequent sheet metal forming process. In order to gain more knowledge about the process chain a numerical approach is performed. In this work, the influence of a coating using Bainidur® AM applied by DED-LB/M on the formability of the case hardening steel 16MnCr5 in a deep drawing process is evaluated. For this purpose, a numerical model is built and validated by comparison with experimental results. The finite-element-model serves as the basis for the investigation on the influence of the location of the additively applied coating on the deep drawing process and also enables a deeper understanding of the process.

Flexible medium forming is one of the main processes to manufacture lightweight component of thin-wall sheet metal. The fairing of spherical bottom cylindrical features is an important part of the spacecraft structure. The traditional deep drawing process has some difficulties such as low forming limit, poor wall thickness uniformity, and difficulty in quality control. Compared with the traditional rigid die forming method, the flexible die forming has obvious advantages in producing complex shape members and thin-walled special-shaped members. In this paper, the magnetic medium for transmitting force (MMTF), assisted the deep drawing of pure aluminum spherical bottom cylindrical parts (SBCP), is studied. The research results show that the formability and quality of the SBCP can be improved effectively by using magnetic medium-assisted sheet metal drawing process. When the magnetic field is raised from 0 to 0.2 T, the maximum reduction rate of wall thickness is reduced from 18 to 11.5%. The ability of deformation and coordination and the uniformity on each part of wall thickness are significantly improved. The ultimate forming height is increased by about 11%. And the amount of springback is also greatly reduced. It can be seen that the MMTF-assisted sheet metal drawing process provides scientific guidance and new ideas for the formation of complex shaped members.

The transformation of the sheet into a product without failure and excess of material in a deep drawing operation means that the initial blanks should be correctly designed. Therefore, the initial blank design is a critical step in deep drawing design procedure. Consequently, an easy approach for engineers in predicting the initial blank shape is necessary to reduce wastage in material and to overcome the large time consumed in the classical approaches. Thus, the aim of the present investigation is to propose an automatic procedure for the quick sheet metal forming optimization. In fact, a metamodel will be build based on artificial neural networks which will be coupled then with an optimization procedure in order to predict the initial blank shape in a rectangular cup deep drawing operation. The metamodel is built from the finite element simulations using ABAQUS commercial code. This procedure allows a significant reduce of the CPU time compared to classical optimization one. The results show that the desired shape is in good agreement with the one calculated using the optimized blank shape.

A novel deep drawing process for aluminum alloy sheets at cryogenic temperatures